Previous studies have shown that smoking i s associated with a high incidence of certain malignancies and a high incidence of metastatic spread of melanoma. The purpose of the present study was t o examine whether this high incidence of malignancy could be associated with certain aspects of immune function believed to be important in restricting tumour growth. Age-and sex-matched smoking and non-smoking normal subjects and male, smoking and non-smoking melanoma patients, were studied for the natural killing (NK) activity of their blood leukocytes against cultured melanoma and Chang cells. The levels of the various immunoglobulin classes in their sera and the E rosette levels of the normal subjects were also assessed. The results indicate that the N K activity of blood leukocytes from both normal subjects and melanoma patients who smoked was significantly lower against cultured melanoma cells than that of non-smokers. Smokers were also shown t o have lower IgG and IgA immunoglobulin levels i n their sera compared t o nonsmokers but no differences i n the percentage of E-rosetting (T) cells was detected. Recent studies provide some basis for the belief that the low N K activity and immunoglobulin levels i n smokers may be related. These results further suggest that a closer examination of the effects of this environmental hazard on the immune system and i t s relation t o malignancy i s needed.It is well known that smoking is associated with a raised incidence of a variety of malignant diseases such as carcinoma of the lung, oesophagus and bladder (Doll and Peto, 1976). It has also been shown that there is a higher incidence of metastatic disease, after 5 years, in male patients with malignant melanomas who smoke, than in those who are nonsmokers (Shaw et al., 1979). The underlying cause for this association between smoking and the increased incidence of malignancy is unknown and it is probable that multiple factors may be involved, including direct carcinogenic effects of products formed from tobacco during smoking.One of the possible associations, however, that has received little attention, is that related to the effects of smoking on the immune system. There is much experimental evidence from studies on both man and animals to show that smoking causes changes in the immune system (Holt and Keast, 1977) and surveillance by the immune system is considered important in control of tumour emergence and growth.In particular, recent studies have suggested that natural killer (NK) activity may play an important role in tumour surveillance (Kiessling and Haller, 1978; Baldwin, 1977; Hersey, 1979). Research originating in this laboratory has provided additional support for a surveillance role for NK cells in that melanoma patients with low post-operative NK activity against melanoma target cells had a significantly higher incidence of recurrence of melanoma than did patients with higher post-operative NK activity (Hersey et al., 1978).The present study was undertaken to determine whether an association between smoking a...

Objectives: To determine the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection among inmates entering the New South Wales correctional system and to examine risk factors for infection. Design: Cross‐sectional survey. Setting: Reception Centre at Long Bay Correctional Centre, Sydney, New South Wales, June to December 1994. Participants: 408 adult male inmates received at the Reception Centre (28% of the 1450 new inmates eligible for compulsory HIV testing). Outcome measures: Presence of HBV core and surface antibody and surface antigen; HCV antibody; risk factors; inmates' knowledge about risk factors. Results: 37% of inmates tested positive for HCV antibody, 31% for HBV core antibody and 3.2% for HBV surface antigen (indicating recent infection or carrier status). Among those who reported a history of injecting illegal drugs, rates rose to 66% for HCV antibody and 43% for HBV core antibody. Prevalence of HBV and HCV antibodies was similar in Aboriginal and non‐Aboriginal inmates, but HBV antigen carrier rate was significantly higher among Aboriginals (12% versus 2.2%). Knowledge about hepatitis risk factors was poor (only 20% named injecting drug use), although recidivists were significantly better informed than those new to the correctional system. Multivariate analysis identified injecting drug use, past exposure to hepatitis B virus and previous imprisonments as significant predictors for HCV infection, and age over 25 years and HCV antibodies for HBV infection. Conclusions: Results suggest that about a third of adult male prisoners entering the NSW correctional system may have been infected with HBV or HCV. Measures such as education about hepatitis risk factors and HBV vaccination are needed to reduce hepatitis transmission in this population.

Linked administrative population data were used to estimate the burden of childhood respiratory syncytial virus (RSV) hospitalization in an Australian cohort aged <5 years. RSV-coded hospitalizations data were extracted for all children aged <5 years born in New South Wales (NSW), Australia between 2001 and 2010. Incidence was calculated as the total number of new episodes of RSV hospitalization divided by the child-years at risk. Mean cost per episode of RSV hospitalization was estimated using public hospital cost weights. The cohort comprised of 870 314 children. The population-based incidence/1000 child-years of RSV hospitalization for children aged <5 years was 4·9 with a rate of 25·6 in children aged <3 months. The incidence of RSV hospitalization (per 1000 child-years) was 11·0 for Indigenous children, 81·5 for children with bronchopulmonary dysplasia (BPD), 10·2 for preterm children with gestational age (GA) 32-36 weeks, 27·0 for children with GA 28-31 weeks, 39·0 for children with GA <28 weeks and 6·7 for term children with low birthweight. RSV hospitalization was associated with an average annual cost of more than AUD 9 million in NSW. RSV was associated with a substantial burden of childhood hospitalization specifically in children aged <3 months and in Indigenous children and children born preterm or with BPD.

Norwalk-like viruses (NLVs) were detected using a nested reverse transcriptase-polymerase chain reaction (RT-PCR) with primers directed to the RNA polymerase region. Samples were examined from 11 separate outbreaks of gastroenteritis and five sporadic cases of childhood gastroenteritis between 1997 and 2000. Phylogenetic analysis of the 298 bp sequences showed that all strains belong to NLV genogroup II and the majority of the sequenced isolates (30/36) were members of the 95/96-US subset of strains associated with outbreaks recorded worldwide between 1995 and 1996. This was confirmed by analysis of the full length capsid region of a representative Australian isolate. This study demonstrates the usefulness of targeting primers for NLVs to the predominant circulating genotype(s) and confirms the spread of this subtype globally, including the Southern Hemisphere.

This study suggests that RSV infection and influenza contribute to IPD incidence peaks differently for children than for adults. Data from other geographic areas and more rigorous study designs are required to confirm these findings.